How to Make It
Preheat the oven to 400°. In a 10-inch ovenproof skillet, mix 4 teaspoons of the olive oil with 2 teaspoons of the vinegar and a pinch of sea salt. Spread the fennel fronds and stalks in the skillet and top with the onion wedges. Drizzle the remaining 2 teaspoons each of olive oil and balsamic vinegar over the onion wedges and top each one with a bay leaf. Sprinkle with the fennel pollen and a pinch of salt.
Cut out a round of parchment paper slightly larger than the skillet. Crumple the round under running water, open it up and place it directly over the onion wedges. Cover the skillet with foil and bake the onion wedges in the center of the oven for 40 minutes, or until tender. Remove the foil and parchment paper.
Turn the onion wedges and cook over high heat on the stove until most of the liquid in the skillet has evaporated, about 1 minute. Transfer the onion wedges and fennel to a plate, discarding the bay leaves and serve.